Mechanical pencil



March 211, 1950 lllnllllllll'v c. G. NHELSEN MECHANICAL PENCIL Filed March 1a, 1946 INVENTOR CARL G. NIELSEN ATTORNEYS Patented Mar. 21, 1950 UNITED STATES PATENT OFFICE,

2,501,612 I MECHANICAL PENCIL CarlG. Nielsen, Racine, Wis.

Application March 16, 1946, Serial No. 654,871

1 Claim.

This invention appertains to writing and marking devices, and more particularly to a novel mechanical pencil.

One of the primary objects of my invention is to provide a simple and positive means for advancing the lead, said mechanism being of such a construction that the likelihood of the same getting out of order is reduced to a minimum.

Another salient object of my invention is to provide ,a lead advancing mechanism for a mechanical pencil, embodying a resilient follower or pusher rod for the lead and a thumb piece carried by the rear end of the rod normally urged into locking contact with the case of the pencil by the inherent tension of said rod for holding the lead in a set advanced position.

A further object of my invention is to provide a novel casing for the pencil which can be readily fabricated from a single sheet of material, if such is desired, and which can be so formed as to provide a guide bore for the lead and the pusher rod, a storage chamber for reserve leads and a clamp or holder for an eraser.

A further important object of my invention is to provide a mechanical pencil which is so constructed that the same can be readily made in a thin flat shape whereby the pencil can be effectively used as a book mark, letter opener, etc.; the flat shape of the pencil also giving ample fiat faces for receiving engraving, advertising matter, and the like.

A still further object of my invention is to provide a practical mechanical pencil of the above character, which will be durable and efficient in use, one that will be simple and easy to manufacture, and one which can be placed upon the market at a low cost.

With these and other objects in View, the invention consists in the novel construction, arrangement and formation of parts, as will be hereinafter more specifically described, claimed, and illustrated in the accompanying drawing, in which drawing:

Figure 1 is an edge elevational view of one preferred form of my pencil.

Figure 2 is a longitudinal sectional view through the pencil.

Figure 3 is a rear end elevational view of the pencil casing, the eraser, eraser cover and lead advancing rod being shown removed.

Figure 4 is a front end elevational view of the casing for the pencil.

Figure 5 is an enlarged fragmentary detail longitudinal view through the rear end of the pencil showing a modified type of eraser which can be associated therewith, the view being taken at right angles to Figure 2. v

Referring to the drawing in detail, wherein similar reference characters designate corresponding parts throughout the several views, the letter M generally indicates my improved mechanical pencil and the same includes an elongated casing l0 preferably, but not necessarily, formed from sheet metal. This casing canbe economically stamped from a single blank of sheet material and thereafter folded into shape. In the drawings, I have shown the casing constructed from a single blank of sheet metal, and this blank is folded longitudinally to provide a connecting edge wall I l and abutting side walls l2 and 13. The edges of the blank are shaped to permit the interfitting thereof during the folding of the blank, and as illustrated in Figure 4, one edgeof the blank can be provided with a longitudinally extending tongue I 4 which can be received in a longitudinal groove l5 formed on the inner surface of the other edge. As is clearly shown in Figure 4, the edge carrying the groove I 5 is curved over into engagement with the rib defining an edge wall IS. The forward end of the pencil casing I I! is tapered as at 11 and the adjacent faces of the walls I2 and I3 are grooved to provide a centrally extending bore or channel It. The pencil lead 19 is 'slidably received in this bore or channel and the side walls H and I2 at the extreme forward end of the pencil are slit as at 20, and the portions of the casing on the opposite sides of the slit can be slightly pressed inwardly to provide resilient fingers 2| for gripping the lead.

At one side of the central bore or channel i8 is provided a longitudinally extending chamber 22 and extra reserve leads can be placed in this chamber. This chamber opens out through the rear end of the pencil. At the extreme rear end of the casing, the side walls 12 and [3 can be flanged outwardly to provide spaced lips 24 between which can be inserted any preferred type of an eraser. A cap 25 can be slipped over the lips 24 to house the eraser, should such be desired.

As brought out in the objects of the specification, I employ a novel lead advancing mechanism, and this lead advancing mechanism includes a resilient pusher or follower rod 26 which is slidably mounted within the bore I8 in rear of the pencil lead [9. The casing l0 itself is formed to cooperate with this advancing rod, and consequently, the wall It adjacent to the rear end of the pencil is cut away to expose the edges of the side walls I 2 and I3. and these edges are provided 'with rack teeth 21. The adjacent faces of the side walls 12 and 13 at this point are reduced in thickness to provide a slot 28 which communicates with the axial bore Hi. The inner or rear end of the resilient follower rod 26 has formed thereon an outwardly extending operating arm 29 which extends through this slot, and this arm has connected therewith a thumb piece 30. The inner face of the thumb piece has formed thereon teeth 3| which mate with the teeth of the rack bars 21. The inherent tension of the rod 26 normally holds the teeth of the thumb piece 30 into engagement with the rack bar so that the rod 21 will be held in a set position.

When it is desired to advance the lead IS, the thumb piece 30 can be forcibly slid over the rack teeth or the thumb piece 30 can be grasped in the fingers and pulled outwardly away from the racks 21, after which the rod can be pushed forward.

In lieu of slidably mounting an eraser between the flanges or lips 24 and providing an extraneous cover 25 for the eraser, I can utilize an eraser 32 (see Figure 5) held in a holder 33. The holder 33 can be detachably mounted between the flanges or lips 24 and when the eraser is not in use, the holder and the eraser can have its position reversed so that the eraser will be positioned between the flanges or lips with the holder 33 extending outwardly. The holder in this position will form a finishing piece for the case.

While I have shown the pencil casing formed flat, so as to provide a thin pencil, obviously, the casing can be made in other shapes.

However, it is preferred to make the casing shown, as this provides a thin flat pencil which can be used as a book mark, letter opener, or the like.

It is also obvious that I can provide two or more bores 18 with lead advancing mechanism in each bore so that a plurality of writing points will be had for difierent colored leads.

Changes in details can be made without departing from the spirit or the scope of my invention, but What I claim as new is:

A mechanical pencil comprising a casing having a longitudinal lead receiving bore, a resilient pusher rod for the lead slidably mounted in said bore, said casing being provided with a slot communicating with the bore and ratchet teeth at least on one side of the slot, a laterally extending arm on the inner end of the rod extending through the slot, and a finger piece secured to said arm and movable with the arm and rod as a unit having teeth for engaging the rack bar, the inherent resilency of the rod holding the teeth of the finger piece in engagement with the rack bar.

CARL G. NIELSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 561,734 Steele June 9, 1896 903,873 Lampson Nov. 17, 1908 1,342,416 Borbeck June 8, 1920 1,975,788 Harris Oct. 9, 1934:

2,259,133 Harper Oct. 14, 1941 FOREIGN PATENTS Number Country Date 600,833 France Nov. 23, 1935 

